Clivias are easily propagated by seed or division. However, unless you are very patient, it is often better to purchase a full or part-grown plant. It often takes 4 to 5 years for a seed grown plant to flower, with some species taking up to 10 years, and, whilst some plants produce many offsets and can be divided regularly from an early age, others rarely produce offsets and may take many years before producing their first one.
Growing from seed
Seed can be harvested when the berries soften. A sure sign is that the berries change colour from green to orange or yellow, but even green seed pods are OK, so long as they have started to soften. Each berry must be peeled and all of the membrane surrounding the seeds removed.
Growers vary in how they germinate the seed. Our technique is to dust the freshly harvested seed in Mancozeb and then press it into trays of new seed raising mix and water well. Clivia seeds should not be buried as they photosynthesize therefore most of the seed must be exposed to light.
The trays of seed are placed in a covered, heated propagation tray and the mix kept moist until they germinate. Seeds sown in summer do not require the heated tray. Germination times vary, with most sprouting within a few days and others taking up to a few weeks.
To avoid breaking the tender new roots, seedlings are potted up to a small sized tube pot before their roots reach the bottom of the seedling tray.
Growing from division
Some Clivias readily produce offsets. These can be left to form a clump of plants or can be removed when large enough. Offsets with less than about six leaves are best left on the parent plant.
Divisions are best removed when you are next repotting the parent plant. Gently untangle the roots, removing any dead or broken roots. As best as possible identify which roots belong with the offset and which with the parent plant and make a sharp straight cut to separate the two. Many gardeners recommend applying a fungicide to the severed sections prior to repotting in separate pots.
To remove divisions from plants growing in the garden it is best to dig up the whole clump, taking ample soil from all around the plant to avoid damaging too many roots. It is not an easy task to dig up a whole clump of Clivia from the garden without damaging them. So unless you are fortunate enough to have extremely loose, soft soil or compost, consider this a two person job.